Land mine

ABSTRACT

1,176,352. Land mines. INDUSTRIEWERKE KARLSRUHE, A.G. 9 Feb., 1967 [16 April, 1966], No. 6267/67. Addition to 1,005,388. Heading F3A. The land - mine of parent Specification 1,005,388 is modified by a cover member 3 having a spherical surface 51 with a centre of curvature which lies above the mine body, or in an upper part thereof, and which is supported by an annular member with an upper web 52a, having a conical surface supporting the surface 51 of the cover member, a cylindrical web 52c forming an axially directed guide, and a web 52b disposed between the webs 52a and 52c, and having a lower conical surface supported by a spherical surface 53 of an annular elastic buffer member 54, having a centre of curvature below the mine or in a lower part thereof. The web 52c is guided on a fuse receiver member 55 which is connected to the mine casing by rivets 56. The material of the spherical surfaces 51 and 53 is harder than that of the webs 52a and 52b, so that when the cover member is subjected to heavy loading its freedom of movement is ensured. The edge 52bk of the web 52b can abut an edge 52k of the member 55, and act as a shock absorber. A fuse is retained in the member 55 by springs 60. An arming device comprises lugs 67 which project above a cover 62 and entered from a rotatable ring 66 having recesses 68 into which pins 64 can move to release a slider 63 and allow it to be moved towards the fuse by a spring 69. An opening in the bottom of the casing 1 is closed by a metal cover 57. A heat fusible screw 58 is located in the side of the casing 1, together with an auxiliary detonator 59, so that the mine can be used for demolition work.

Sept M 1965 P. MADLENER ETAL. 3,205,817

LAND MINE 4 Sheets-Sheet 1 Filed April 27, 1962 INVENTORS MZeer"IIIIIIIIIIIII l BY man., @1w .bwa-u* ATTORNEYS Sept 14, i965 P.wumLl-:Nf-:r-ev ETAL 3,205,817

LAND MINE Filed April 27, 1962 4 Sheets-Sheet 2 BY om ,(32% w .CUaJzMATTORNE Sept M, 1965 P. MADLENER ETAL 3,205,817

LAND MINE Filed April 2'?. 1962 4 Sheets-Sheet 3 INVENTORS BY www. G24s. bo alza-w ATTORNEYS Sept 14, 1965 P. MADLENER ETAL 3,205,817

LAND MINE Filed April 2'7, 1962 4 Sheets-Sheet 4 flfy.

INVENTORS BY wan-,wM-wm ATTORNEYS United States Patent O J 4 Claims.(Cl. 1oz-s) This invention relates to a land mine to be dropped fromairplanes, moving tanks, or the like. This mine has a safety devicewhich is operative before the ignition setting of the iiring pin igniterand has an actuating element which is swivel-mounted, which actuatingelement cornpletes an idle motion if contacted by detonation waves,especially of a nuclear type, while it actuates the tiring pin whencontacted in an oblique manner.

Land mines are normally planted by hand with the utmost caution. Themines, the respective igniters andthe detonating caps are transportedseparately to the location where they are to be used and onlythere, thedetonating caps and the igniters are attached to the mine. Each mine isburied at a certain depth and is camouaged. After this, the safety catchof the igniter is released and the mine will respond to a predeterminedpressure.

This pressure may be achieved by a vehicle moving over the mine as wellas by detonation waves. Numerous attempts have been made to prevent thislatter, unwanted actuation by building the impact elements, i.e. thepressure lid, as small as possible. Another attempt was made to keep thedistance between the actuating element and the igniter top so large thatby impact the duration of the pressure would not be sufficient toovercome the force of inertia to travel this distance. A further attemptwas made to eliminate this disadvantage by using an elastic deformationlink between the actuating element and the igniter which link wouldabsorb the first shock and act as a brake. Another possibility is toinsert a pneumatic equalizing pressure cushion; this cushion will resista transient shock, but will break under constant pressure.

It is further known in the art to use an actuating element with abowl-shaped wall placed in a bowl-shaped bushing. The actuating elementis supported by an equally distributed vertical pressure and resistsshocks such a's encountered in a detonation wave, without puttingpressure on the igniter. This structure has shown satisfactory resultsin the case of small mines (personnel mines). However, in the case oftank mines where the actuating elements cannot be below a certain sizebecause of the structure of the treads, the sudden pressure is of suchforce that the possible constructive support areas are no longer enoughto receive this force.

As a last requirement, it is necessary to lay the mines at such adistance from one another that the detonation of one mine does notinfluence the remaining mines.

All these structures are satisfactory as long as the detonation wavesare of the normal type, spreading with high velocity and disappearing inthe same manner. In most cases, the structures known in the art willfail as soon as the mines are touched by a series of quick detonationwaves; they fail especially, however, if touched by nuclear explosionswhich have an extremely high pressure lasting for several seconds.

In the subject structure, the mines are to be dropped from a helicopteror from a moving vehicle and, therefore, it is to be expected that inthe known art the actuating element would be released by the impact ofthe mines falling to the ground and further, that they would be plantedirregularly or at short distances from one another which would favor atransmission of detonations;

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and still further, the mines would come to lie at times upside-down,particularly in soft soil.

Considering the required speed when laying the mines as well as the lackof space in a plane or vehicle, it is necessary that the mines arebrought abroad with the detonating caps and igniters already inserted.However, they have to be constructed in such a manner that the igniteris properly secured and that this safety device can be removed in onesimple step. As a safety measure during the process of planting themines, it is further necessary to provide a timing device whichascertains that the mines will respond to pressure only after apredetermined length of time. This timing device must switch onautomatically during the process of dropping the mines. Finally, themine should also meet the requirement for a mine which can either beused as a normal mine or as a mine having a tamper-proof device toprevent it being rendered harmless by the enemy,

To meet this requirement, the subject invention provides an actuatingelement in the form of a pressure lid characterized by bendingresistance, which pressure lid leans against the mine case byinterconnecting a hardelastic inner and an elastic outer ring case,which pressure lid tilts across the surface of the inner ring caseduring eccentric pressure.

The diameter of the pressure lid, which is constructed with doublewalls, is approximately the same as the body of the mine so that theexplosives will remain at all times beneath the treads of a vehicle.Further, the pressure lid provides a screw cap with a conical openingwhich, when the safety catch is released, presses against a gliding:pressurizer located in the igniter case. The pressurizer transmits themotion received through the tiring pin to a concentric running mechanismof known structure, one endl of the ring pin being connected to thepressurizer, the other end benig connected to the tubular extension ofthe running mechanism. The tubular extension of the running mechanism isrotated by a flat spiral spring which rotary motion is transmitted to acontrol case which is rigidly connected with the tubular extension.After a predetermnied revolution (safety time), this control case willpull the cylinder block located in an axially movable sliding sleevedownwardly, creating a ring-type cavity. The cavity permits a secondcylinder blocking device to yield, which blocking device includes a pairof members which engage a recess in the tiring pin and are kept in ablocked position by means of a projection on the igniter case. Afterremoval of the transportation safety plate, the running mechanism isactuated by screwing in the screwing cap. Movement of the cap causes thefiring pin to move downwardly whereby a blocking ball positioned in thewall of the tubular extension is actuated by a bobbin mounted on thering pin which actuates a slider. The slider in turn initiates therotation of the running mechanism. Mounted on the igniter case is awrapper cap holding the pressurizer in the igniter by means of a spring.The igniter has a tamperproof device for preventing rendering itharmless. In this arrangement, the wrapper caps are removed and twoshearing pins which connect the pressurizer with the igniter case, aresheared off by screwing in a screw cap. When the screw cap is removed,the cylinder block moves upwards exposing the ring pin. By means of thisconstruction, the subject invention meets the above mentionedrequirements.

These and various other objects and features will be more clearlyunderstood from a reading of the detailed description of this inventionin connection with the drawing in which:

FIG. 1 shows a mine according to one embodiment of the invention invertical cross section;

FIG. 2 is another exhibit of the outer ring case in cross section;

FIG. 3 is a cross section of the igniter in stationary position;

FIG. 4 is a horizontal cross section of the diameter on the level of thelower cylinder block (taken along the line A-B of FIG. 3);

FIG. 5 is a vertical cross section of the igniter after removal of thetransportation safety device with the running mechanism turned on;

FIG. 6 is a vertical cross section of the igniter in actuating position;

FIG. 7 is a vertical cross section of the igniter with a safety deviceagainst further handling (without wrapper cap, with shearing pins); and,

FIG. 8 is a vertical cross section of the igniter with 'sheared offshearing pins in actuating position.

The mine case 1 (FIG. l) which, for example, is made of a light metalalloy that can be welded, contains explosives 2. Mounted on the mine isa pressure lid 3 which, when receiving pressure, acts on a centrallyattached igniter mechanism 4. The pressure lid is of double thicknessand has the highest possible bending resistance while using a minimum ofweight exertion because of its forrn. Its diameter approximately equalsthat of the mine case and is therefore big enough so that a lifting armis always ready to release the firing pin. The independently suspendedouter rim of the pressure lid is supported by elastic and conical ringcase 5 which is vulcanized or riveted and which simultaneously protectsthe inside of the mine against dampness. The diameter of the pressurelid is large enough so that in softer soil, in an upside-down position,enough pressure may be developed to actuate the mine. The center part ofpressure lid 3, together with a round or conical plate 6, is supportedby a second ring case 8 which is inserted into a ring plate 7. Ring case8 has an arched surface of hardelastic material which, in stationaryposition only, touches in linear contact. Any chosen undulatory form canbe used for ring 5. The material used in this ring has been keptsomewhat more pliable than that of the inner ring case 8.

When subjected to horizontal pressure from all sides, as caused bynuclear detonation waves, the hard-elastic inner ring case 8 pressesagainst the round or conical plate 6 of pressure lid 3 until said plateis illed out. The ring case 8 may have openings such as holes, slits,etc. (not shown), so that the hard-elastic material can easily yield andmold into plate 6. After that, the support is rigid. Sudden pressures onpressure lid 3, therefore, can be intercepted quickly and within a shortdistance and no explosion is actuated by detonation waves, for thisshort distance is not enough to release the igniter 4.

When subjected to pressure on only one side of pressure lid 3, theconical elastic outer ring case 5 yields to the outside and lid 3 tiltsacross the arched surface of ring case 8. Thereby, a movementperpendicular to the mine axis is accomplished and this motion istranslated into movement parallel to the mine axis by the cooperation ofa conical cavity member 9 positioned in the screw cap 10 of pressure lid3 and pressure pin 11. Horizontal movement of member 9 causes verticalmovement of pressure pin 11.

In view of the requirements regarding the dropping of these mines,igniter 4 is screwed to the mine case by means of threads 12. Firing pin13 is kept in a stressed Aposition by means of radially arrangedcylinder block which serves as a guide for tiring pin flange 20 attachedto the lower part of firing pin 13. The upper end 21 of ring pin 13 isparallel to the axis in pressure pin 11. Firing pin ange 20 restrainsthe tiring pin spring 22 which, with its upper end, engages the lowersurface of pressure pin 11. The upper part of the tubular extension 19,which projects beyond the running mechanism, is Connected solidly withcontrol case 23. Control case 23 supports second cylinder blocks 25located in a round groove or recess 24 (FIG. 3), blocks 25 are placedradially in sliding sleeve 26. The outer ends of these cylinders areplaced in round groove or recess 27 located in the inner wall of theigniter and thus block sliding sleeve 26. This sliding sleeve isarranged so that it can slide along the inner wall of the igniter,secured against rotation by screw 29 located in slit 28 which slit isparallel to the axis.

Pressure pin 11 is of cylindrical shape on the lower part and slidesalong the inner wall of sliding sleeve 26. Spring 16 rests with itslower end on sliding sleeve 26. In safety position, sliding sleeve 26 ispushed upwards so that it rests against projection 30 in the ignitercylinder wall. In this position, if pressure pin 11 is being pusheddownwards, cylinder block 14 of the firing pin cannot yield to theoutside; the firing pin is therefore locked to pressure pin 11.

In safety position, a separator piece 31, made preferably of metal, islaid underneath screw cap 10 of pressure lid 3, which separator pieceprevents a complete screwing in of the lid 3. The size of this separatorpiece 31 is measured so that when a tilting of pressure lid 3 occurs,pressure pin 11 of igniter 4 is not being burdened.

Immediately before planting the mine, `the separator piece 31 is removedand screw cap 10 of pressure lid 3 is fully screwed in. Pressure pin 11of the igniter is thereby moved down at a predetermined rate. Sincetiring pin 13 is in contact With pressure pin 11 through cylinder block14, the ring pin moves down at the same rate, grazing globe 32 withflange 20 or moving a similar projecting nozzle positioned in the wallof tubular extension 19. This globe or nozzle yields and switches on therunning mechanism 18 by actuating slider 37 which acts on agitator 38 ofthe running mechanism.

Running mechanism 18 is set so that the tubular extension 19 willcomplete one rotation during a predetermined length of time. This periodcan be called safety time during which the igniter cannot be released orbe influenced through pressure on t-he mine, because the tiring pin 13is locked to the pressure pin 11 by cylinder blocks 14. This period mayamount to 5 to 10 minutes. Control case 23, which is connected withtubular extension 19, participates in this rotation so that in the nalposi-tion (FIG. 4) two opposite vertical grooves 33 which are parallelto the axis are positioned in the control case 23 ybefore blockcylinders 25 land sliding sleeve 26. Through the force of supportingspring 16, sliding sleeve 26 strike-s down, forming ya ring-type cavity34 (FIG. 6) between the wall of the igniter case and the wall of thepressurizer cylinder. If, after sliding .sleeve 26 strikes down, `aneccentric force touches the igniter, thereby mov- Iing pressure pin 1'1downwards, the tiring pin-cylinder blocks 14 positioned in cavity 34 areable to yield to the outside, exposing tiring pin 13. Under theinfluence of ring pin spring 22, ring pin 13 will strike and igniteigniter cap 35.

With a minimum variation, the described igniter may be provided withtamperproof means for preventing rendering i-t harmless. Thus, theigniter may be used as described above o-r in its normal condition, inwhich it is simple to render the mine harmless. For this purpose,pressure pin 11 (FIGS. 7 and 8), which was `made of aluminum in theabove embodiments, preferably should -be made of steel. Pressure pin 11is now pressed against the igniter case by two shearing .pins 36.Additionally, wrapper cap 17 has been removed before insertion of theign'iter. When screwing in lid screw cap 10, pressure pin 1-1 is againpushed downwards, whereby running mechanism 18 is actuated throughtiring pin ilange 20. At the same time, both shearing p-ins 36 aresheared off. Subseqruenltly, supporting spring 16 presses pressure pin11 against screw cap of pressure lid 3. As soon as screw cap lll hasbeen loosened, pressure pin 11 moves upwards until b-oth cylinder blocks14 .of tiring pin 13 touch the upper edge of the igniter ca-se (FIG. 8),move outside and release the firing pin.

In summarizing, it is to be noted that among others the followingfeatures have been described:

(1) A time-out safety mea-ns including a running mechanism I18 having allat spiral spring, tubular extension 19, slider 37, agitator 3S andilange globe 32 is actuated by the ring pin flange 20 when the safetyseparator piece 31 is removed .and the screw cap 10 is rotated to causethe conical cavity member 9 to engage pressure pin 11.1 `and move thefiring pin ilange 20 (coupled to the pressure pin 11) downwardly intoengagement with llange globe 312.

(2) Aiiter the timeout safety means is actuated, the running mechanism18 rotates tubular extension 19 and the control case 23 until 'chevertical grooves 33 are aligned with .the second cylinder blocks 25thereby permitting support spring 16 to push sliding sleeve 26downwardly to create a cavity 34 (IFIG. 6) between the periphery ofpressure pin 1|1 and the portion of the igniter means container belowprojection 30. 'Ilhe mine is now armed and will be .actuated .by anyIuneven pressure on the lid 3 which is sufficient to deform the elasticring 5 and cause the conical cavity member 9, supported in the screw cap10, to force the pressure pin 1-1 downwardly until the cylinder blocks.14 are in the pla-ne .of the cavity 34. At this point, the firing pinspring 22 overcomes the inertia of the cylinder blocks 14, whichnormally engage the recess in pin 13 and force the firing pin 13 intoengagement with the iguiter cap 35, which explodes explosive 2.

Finally, it should be noted that a mine in which the lid does not tiltsideways may be provided with a normal igniter as well as with anigniter having a safety device.

While several embodiments have been shown, it is understood that theconcepts thereof could be applied to other embodiments without departingfrom the spirit and scope of this invention.

What is claimed is:

1. A land mine to be dropped from a moving vehicle, comprising a fusehaving `a spring loaded pressure pin with a rounded head, timed safetymeans operable to arm said mine after a predetermined time delay periodin response to movement imparted to said pressure .pin by pressure onsaid rounded head, a double walled pressure lid having an outer edge andinner conical surface, a substantially enclosed mine case, the outeredge of said pressure lid having in contact therewith a supportingelastic ring resting o-n the mine case, said pressure lid further havinga screw cap retainer for adjusting the position of the pressure lid, aconical cavity member loosely enclosing s-aid rounded head of saidpressure pin, .a further elastic ring Ihaving a rounded outer surfacelocated on the mine case, on which outer surface rests said coni-calarea .of the pressure lid to afford a mating surface thereby permittingthe pressure lid to tilt the conical cavity member relative to therounded head of the pressure p-in to thereby move the pressure pin.

y2. A land mine according to claim 1, having firing pin retainer meanscomprising a tiring pin movably positioned within the pressure pin headand forming part of the pressure pin, said tiring pin having an annulargroove, an expandable retaining collar fitting into said groove, andcylinder locking means located inside the safety means retain-ing saidcollar .in a position whereby it rests in said groove to hold saidtiring pin, a control case included in said safety means having thereina sliding sleeve movable out of said cylinder locking means by ya changeof position of said spring loaded press-ure pin to release saidretaining collar from the groove in the tiring pin.

3. A land mine according to claim 2, characterized in that the iiringpin has a need-le end carrying a guiding ange, a movable cam located inthe opening of the wall of the tubular extension reaching into the .pathof said guiding ilange, a cam operated slider which sets in motion saidsafety .means delay period, said slider mounted for yactuation bymovement of said ca-m, and means operable by said screw cap on saidpressure lid to move said pressure pin and thus to move said guidingange into contact with said cam.

4. A land mine according to claim 3, characterized in that said pressurepin is secured by means of two shearing pins positioned withcorrespond-ing means to shear olf when .the screw cap is moved to Iarmthe mine.

References Cited bythe Examiner UNITED STATES PATENTS 2,376,362 5/45AAdleman 102-8 2,466,867 3/48 Traylor 102-8 X 2,678,604 5/54 Walker102-8 2,857,842 I10/58 -Malim 102-8 2,863,391 12/5'8 Diels 102-82,941,472 6/60 lLee et al, 102-70 3,030,887 .4/62 Simmen et al 102-84BENJAMIN A. BOROHELT, Primary Examiner.

ARTHUR M. HORTON, SAMUEL W. ENGLE, Examiners.

1. A LAND MINE TO BE DROPPED FROM A MOVING VEHICLE COMPRISING A FUSE HAVING A SPRING LOADED PRESSURE PIN WITH A ROUNDED HEAD, TIMED SAFETY MEANS OPERABLE TO ARM SAID MINE AFTER A PREDETERMINED TIME DELAY PERIOD IN RESPONSE TO MOVEMENT IMPARTED TO SAID PRESSURE PIN BY PRESSURE ON SAID ROUNDED HEAD, A DOUBLE WALLED PRESSURE LID HAVING AN OUTER EDGE AND INNER CONICAL SURFACE, A SUBSTANTIALLY ENCLOSED MINE CASE, THE OUTER EDGE OF SAID PRESSURE LID HAVING IN CONTACT THEREWIOTH A SUPPORTING ELASTIC RING ESTING ON THE MINE CASE, SAID PRESSURE LID FURTHER HAVING A SCREW CAP RETAINER FOR ADJUSTING THE POSITION OF THE PRESSURE LID, A CONICAL CAVITY MEMBER LOOSELY ENCLOSING SAID ROUNDED HEAD OF SAID PRESSURE PIN, A FURTHER ELASTIC RING HAVING A ROUNDED OUTER SURFACE LOCATED ON THE MINE CASE, ON WHICH OUTER SURFACE RESTS SAID CONICAL AREA OF THE PRESSURE LID TO AFFORD A MATING SURFACE THEREBY PERMITTING THE PRESSURE LID TO TILT THE CONICAL CAVITY MEMBER RELATIVE TO THE ROUNDED HEAD OF THE PRESSURE PIN TO THEREBY MOVE THE PRESSURE PIN. 